Question 774468
Red Riding Hood drives 432 miles to Grandmother's house in one hour less than it takes the Wolf to drive the same route. Her average speed is 6 mph faster than the Wolf's average speed. How fast does each drive.
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let x=wolf's ave speed
x+6=Red Riding Hood's ave speed
travel time=distance/speed
{{{432/x-432/(x+6)=1}}}
LCD:x(x+6)
432(x+6)-432x=x^2+6x
432x+2592-432x=x^2+6x
x^2+6x-2592=0
(x+54)(x-48)=0
x=-54 (reject)
or
x=48
x+6=54
wolf's ave speed=48 mph
Red Riding Hood's ave speed=54 mph